Luminous discharge tube and system



July 24, 1956 F. B. MAYNARD 2,756,366

LUMINOUS DISCHARGE TUBE AND SYSTEM Filed April 1, 1954 3 Sheets-Sheet l QT? j.

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QQ II INVENTOR.

+4 FRED B. MAYNARD OENEY July 24, 1956 MAYNARD 2,756,366

LUMINOUS DISCHARGE TUBE AND SYSTEM Filed April 1, 1954 3 Sheets-Sheet 2 0 1 a 213 2, 5 1 El 9 101' 30. 1e 1% T 3 a 5 2.

1e T 111-: J INVENTOR.

FEED B. MAYNARD QTTO N EY July 2 4, 1 F. B. MAYNARD LUMINOUS DISCHARGE TUBE AND SYSTEM 3 Sheets-Sheet 3 Filed April 1, 1954 AmvmzPTmwaoz awemtza m D R R v: R.N E mm .6 MM /o QW w I D H J E 3 Pas United States Patent LUMINOUS DISCHARGE TUBE AND SYSTEM Fred B. Maynard, Cedar Grove, N. J., assignor to National Union Electric Corporaticn, a cnrporatiun of Delaware Application April 1, 1954, Serial No. 420,366

12 Claims. (Cl. 315334) This invention-relates to luminous discharge tubes, and more especially it relates to'such tubes wherein a plurality of separate luminous displays can be selectively produced.

A principal object of the invention is to provide a novel and simplified luminous display tube for producing difierent luminous displays within the same viewing boundary.

Various forms of luminous discharge tubes have been proposed heretofore, examples of which are the so-called counter tubes wherein a plurality of luminous targets are arranged in spaced side-by-side array. These targets are provided with a common electrode, and by means of a suitable switch, each target can be individually and selectively illuminated. One of the disadvantages of this conventional construction is that it is not possible to produce variable luminous displays'within the same single boundary. For example, if the conventional device is to be used to display the numerals 1 to '10, thenat any given confined boundary only a single numeral can be dis- ;played. This necessarily follows from the factthat the individual luminous targets are arranged side-by-side.

Therefore, in order to changethe display, forexample from numeral 1 to numeral 9,.the visual displaywill not occupythe samepositionin front of the observer for each of these numerals.

Accordingly, it is anotherprincipal object of ,thisin- .vention to'provide .anovel luminous display tubewherein at-any given viewing area or boundary, anydesired luminous indicia, whether numerical, alphabetical, or other symbol, can be changed at will.

Another object is.to;pr ovide.a novel construction for a plural-indicialuminous display tube, wherein the luminouselectrodes are in physicallysuperpcsed or stacked array,..whereby ,a series of such tubes can be arranged in columnar arrayso as to set up any desired intelligence message or visual di splaywhich. can-be changed at .will.

A-feature oftheinvention relates to a plural-indicia luminous discharge tubeemploying a series of :fine wire luminous targets inspaced stacked array,-whereby any target in the stack can ;be selectivelyilluminatedand .viewedwithout. any substantial obscuring by the remainin tar ,illurmflated with cathode glow byv (causing the remaining v targets to act as -E1, Qdcs. necessity of using aseparate common anode for all the This arrangement avoids the cathode, glow. targets.

,Another feature relates to an improved plural-indicia luminous discharge tube employing standard base constructionseuchasemployed inconventional radio tubes and the like, and whereby any one of a series of luminous indicia. may be displayed and viewed from one end of the tube within the same viewing area.

Another feature relates to the -novel organization, ar-

-rangernent, and relative location of-parts which cooperate 2,756,356 Patented July 24, 1956 to provide, an improved;plural-indicia luminous discharge tube. -Other features and advantages not particularly enumeratedwill .be. apparent .after a consideration of the following detailed descriptions. and. the. appended claims.

In the drawing,

Fig. 1 is a vertical'elevational view of a tube according to the invention;

Fig. 2 isabottom. view of-Fig. 1;

Fig.3 is a, top. plan view of Fig. l in enlarged form;

Fig.4 isasectional view of'Fig. 3 taken along the line 4-4 thereof;

Fig. 5 is anrenlarged. detail viewshowing the manner of supporting. each of the fine Wire electrodes of Figs. 1 to 4;

Figs. 6A,6l-.are sectional views of Fig. 4 taken along the lines 6A,6A to 6J 6J respectively, and viewed in the directionofthe arrows;

Fig. 7 is a schematic wiring diagram of the circuit arrangement for selectively. energizing the electrodes of the tube of the preceding figures;

Fig. 8 is, a schematie'diagram of an automatic time display system usinga multiplicity of the tubes according to the invention.

Referring to v Figs.- 1. to 5,:the tube comprises an enclosing bulb or envelope;12 which is sealed invacuum-tight manner to a'header 13 ,and through which header are providingten separate lead-ins for the respective ten cathqdeglow electrodes to ,bekdescribed. The bulb 12 maybe'pfglassandmaymbeevacuated and then filled with a suitable inert gas or mixture of inert gases through h exha ttuhu1a ion..14.whichan her p n e tipp otr andsealedin the, usual ,manner. The inert gas may be neon, argon, helium, or any mixture thereof at a predetermineidpressurg'for example 25 mm. of mercury.

"Prior to scaling the bulb 12 to the header v13 there are welded tothe, internally projecting ends of the pins numbered '1 to v10 respective metal uprightsor rods let-10a. Each .of these rods iscf progressively greater length. The ro'd 1a isjbent asjshownin Fig. 4, so that the upper ends of all the rods 1a-%10a are in a circular array. .Telescopedmver eachro'd is a corresponding ceramic sleeve 1b-j10b. Preferably, each of these ceramic sleeves is'somewhat shortenin; length than the rod over which it is telescoped .so as to provide an extending portion to which the corresponding one of each often wire electrodes'is welded. '.,'I'hese.ten. electrodes are respectively pre-bent to the shape of. the desired symbol or indicia. Merely forpurposes of'illustration, it will be assumed that the device lis to be used as a numericalindicator in which event each, of the-ten electrodes is bent-to the shape of the corresponding numerals 1 to10.

As showrimore clearly inthe sectional views of Figs. 6A-6l, each of the numerically shaped wire electrodes '1e,10e is'in the formof an incomplete electricalloop. Thus, in the case of'the'electrodeMathew is provided a minute gap 15 so that-itappears'visually as a substantiallycompletezero digit, but is still a non-inductive loop.

Similarly, inithe case of -each ofthe electrodes 9e, 3e, 6e, and4e, where the portion of the electrode Wire is bent and crossessitself, at/the crossing region there is a space so as 'to .avoid'the formationcf a complete inducfive-1100p.

As shown more clearly in Fig. 5, each of the wire electrodes has a radially extending portion 16 which is Welded to that portion of its corresponding metal upright, and each wire electrode is so attached to its corresponding metal upright that-it'extends in a plane substantially perpendicular to the centrallongitudinal axis of the bulb 12. Inother words, all the wire electrodes are located in spaced parallel planes considered along the said longitudinal ,axis. figa ip shows ,the normal physical appearance of the device "when yiewed from the upper end of bulb 12 with no electrodes energized. Each of the wire electrodes lea-s, is of sulficiently fine cross section that when any given electrode is energized and illuminated by its cathode glow its illuminated character is not to any substantial extent obscured by. theintervening unenergized .wire electrodes. for example, each of the electrodes 1e-10e may be made from tungsten wire of .005 inch cross section, l-lpwever tungsten wire, 'because of .its springiness, is somewhat difiicult to shape and preferably, therefore, each' of the wire electrodes is formed fromnickel wire ofapproximately .908 inch cross section. a Z w In order to confine the cathode glow entirely tothe indicia shape ofeach electrode, the portionsof the wire which do not form an essential partof the desired indicia are coated with a suitable insulating .cerarniccement, as indicated by thenumeral 17. To preserve the circumferential spacing of .the insulated uprights lit-10a, these uprights with their ceramic sleeves 1b-10b pass through a circular metal disc18 and this. disc may be held in place on each upright by aninsulatingrefractory or ceramic cement 19. Preferably, the upper face of disc 18 is oxidized or blackened in any suitable way so as to provide a sharp background contrastforeach illuminated wire electrode. Preferably also theinterior surfaceof the bulb 12 beneath the electrodes is provided with .an opaque black coating 20, for exampleof graphite ,or other 1 similar material.

I have found that by selectively applying a negative potential to any one of the abovementioned wire electrodes while maintaining the. remaining electrodes-connected to a positive potential, the desired electrode ,is illuminated with its respective cathode glow. which .is of suflicient intensity so thatv it stands-outandis, not obscured by any of the intervening unenergized electrodes. This efiect is obtained because the cathodev glow is a brilliant illumination and the diameter,,;of,the .glow surrounding the associated wire is severaltimesthe diameter of the wire itself.

I have found also that this result can be achieved by connecting each electrode through, respective -one ofa plurality of impedances or resistances lrt-to, 10r-(Fig. '7), and thence to the positive terminal21 ofa' suitable direct current source. Each of the resistors .1r10r may.;be of the same value. Each of the electrodes 1e-10e "is connected directly by a corresponding wire to arespective terminal 1t-10t of a suitable'com'mut'ator switch whose movable brush 22 is. connected to thenegative terminal 23 of the direct current supply.- As is well known in cathode glow devices, the electrode-which is connected to the positive terminal ofthe power supply does not glow, but the electrode which is connected to the negative terminal glows of a cathodicglow'which is a more or less'close fitting sheath of evenly distributed illumination resulting from ionization of gas particles,f and this illumination glow assumes very nearly an even thickness over the wire electrode area. Therefore, by selectively positioning the brush 22 I have found it possible to selectively illuminate any desired wire electrode. 7

From an examination of Fig. 7 it will be seen that, with brush 22 in contact with terminal 2!, electrodes 1e and 3e-10e are all held at positive voltage through their respective resistors 1r:and 3r--10r. However, since the brush 22 is in contact with terminal 21, the electrode 2e is connected to the negative potential terminal '23 so that only the electrode 2e glows. The remaining electrodes, being at positive potential, the current flow produces sufficient voltage drop across their respective resistors so as to maintain the said remaining electrodes at positive potential. In other words, the particular selected electrode 2e assumes a negative potential with respect to all the remaining electrodes and it alone glows with a cathodic glow. However, by, changing the position of brush 22, any desired one of the electrodes can be illuminated and, because of the fine wire character of the non-illuminated electrodes they do not .to any substantial extent interfere with the effective illumination or glow visibility of the energized electrode. It will be understood, of course, Fig. 7 is essentially schematic and while the electrodes 1e-10e are shown in vertically displaced relation, actually these electrodes are in superposed parallel stacked planes, as shown in the physical view of Fig 4. I Therefore, the tube of Fig. 4 can beviewedthrough its upper end 24 in the direction of the arrows and for any given setting of switch brush 22 one, electrode becomes visibly luminous. a

While the device above described is capable ofnurnerous applications for producing animated or other controlled movable displays, there is shown in Fig. 8 a system for using four of the devices as a time or clock display. In Fig. 8, there are represented by the numerals 25, 26, 27, 28, four devices each of which is identical with the device described above'in connection with Figs. 1 to 5. Merely for simplicity inthe drawing, only one electrode is shown in each of these devices. Thus, in device 25 only electrode 1e isshown and the devices 25-28 are assumed to be mounted so that their upper ends corresponding to end 24 (Fig. 4) are all viewable in end-on relation, namely perpendicular to the plane of the drawing sheet. Inorder to vary the multiple indicia display, there may be provided any suitable motor schematicallydesignated in Fig. 8 by the numeral 29. This motor may be of any well known synchronous type such, for example, asla Telechron motor, conventionally used in electric clocks and whose shaftg30 rotates for example at the rate of six revolutions per hour. Shaft 30'carries an arm 31 having a pin 32 whichis' adapted to engage a six-toothed star wheel 33 atfixed to shaft 38. Thus, shaft 30 rotates at six revolutions per hour," shaft 34 rotates at one revolution per hour, and shaft 38 rotates at i revolutionperhour.

Shaft 30 is mechanically connected to a brush 39 which is adapted to wipe over ten station ary'contacts each of which is connected through a respective resistor 50 to 59 and thence to the corresponding one of the ten lead-in pins of the device 25. The brush 39 is connected to the grounded negative terminal of the volt direct current supply. Thus, in the particular position shown in Fi g. 8, brush 39 applies negative potential to lead-inmember 1 of device 25 alone and thus causes electrode le'alone to be illuminated by cathode glow. The remaining electrodes in device 25 are unilluminated.

The shaft 34 is mechanically connected to'a grounded brush 40 which. is arranged to wipe over stationary contacts. These six contacts are connected 'through respective resistors 60-66 and thenceto respective lead-in members of the device 26. Since the device 26 is to represent the tens digit of the minutes, only six digits (that is, digit 0 to digit 5) are required for illumination in the device 26.- Therefore, it is necessary only 'to energize the numerals representing digits 0' to 5 device 26. Likewise, the shaft 38 is mechanically connectedto two grounded brushes 41, 4 2, which are adapted tg ro tate as a unit. Brush 41 is adapted to engage three stationary commutator segments 43, 44, 45. Brush 42 is adapted to wipe over twenty-four equally spaced stationary contacts at the ratio of one contact perhour. Ten oftbese. contacts are included in-tbe same are subtended-by commu- -tator segment 43. 'The next ten stationary contactsare that showing of emanates included within thejarc subtended by stationary contact ment-45. Commutator-segment "43 is connected-to the tenth lead-in member of 'deviczef28 which is connected to electrode 10e -of'that;device. ,In otherwords, so long as brush-:42 is wiping over the first-setof'ten-:stationarycontacts associated with segment 43, only ,the-zero display Will beproduced on electrode'10e-of device-28. The-device 27 is. arranged to indicate-the units digits (that is, digits'Oto 9) o'f'thehonrs,andthedevice 28 is arranged to indicatetens digits (digitsfl'to 2) of the hours.

As the brush 42 steps one position perihour and so long as brush '41 is'in contact with segment'43, the corresponding units electrode of device 27 will be energized. Thus, in the particular setting shown in Fig. 8, brush 41 is in engagement with segment 43'causing, the zero electrode of device 28 to be illuminated and th e #4 electrode of de- .vice 27 to be illuminated. At the beginning of the eleventh hour, brush 41 engages segment and illuminates the #1 electrode of device. 28. ,At the same time brush 42 engages the #1 contact of this particular set and illuminates the #1 electrode in device 27. At the.,beginning of the twenty-first hour the brush ;41 engages segment 45,to illuminate electrode #Zin device 28 and also to illuminate electrode in device 27. The foregoing cycle of operations is repeated, thus continuously displaying the time on the four ,devices. 25, 2.6, 27, -and-28.

It will be understood, of course, that while one particular type of displaysystenihas-beenillustrated, the plural indicia devices can beusedjor any;other visual display system such, for examp e, as train announcing-systems, and the like. Furthermore, the;,iuvention is v:not litnited to the provision of electrodes in the various devices in the form of numerals. For example, these electrodes in each device may be shaped to the form of letters of the alphabet, and by appropriate commutator means any desired intelligence or message may be instantaneously displayed. Furthermore, while the drawing illustrates the invention in a device having ten coaxially stacked skeleton wire electrodes in each device, it will be understood that a greater or less number may be employed depending upon the type of display system. Furthermore, it is not necessary that all the electrodes be of the same size. For example, electrode 1e may be in the form of a circle and another electrode may have its size shaped so that it fits within the boundary of the first electrode, in which event by suitable switching means one electrode can be maintained steadily illuminated and the other electrode within its boundary can be temporarily illuminated for various display purposes.

Various changes and modifications can be made in the disclosed embodiments without departing from the spirit and scope of the invention.

What is claimed is:

A plural-indicia gaseous glow discharge device, comprising an enclosing envelope containing an ionizable medium and having a transparent portion through which the indicia are viewed, a plurality of separate glow sustaining skeleton electrodes in spaced stacked array and in alignment with said portion of said envelope each of said electrodes being shaped to a distinctive indicia form, all the successive electrodes being spaced from each other and free from intervening light absorption or obstruction elements, and a plurality of lead-in members one for each electrode for selectively causing one electrode at a time to sustain a cathode glow which is substantially completely visible through the skeleton of the adjacent electrodes in the stack.

2. A plural-indicia gaseous glow discharge device, comprising an enclosing envelope containing an ionizable medium, said envelope having a viewing window, a plurality of separate skeleton electrodes each being a conductive member shaped to a distinctive indicia form and for sus taining a cathode glow discharge therealong, means to 'supportall said'electrodes in substantial parallel stacked -array and with all-the electrodes in successive alignment withsaid window, and with the space between adjacent electrodes free from intervening light absorption or obstruction elements, and a plurality of lead-in members one for each of said targets for selectively causing one electrode to sustain a cathode glow which is substantially completely visible through the adjacent skeleton electrode.

3. A'plural-indicia gaseous glow discharge device, comprising an enclosing envelope containing an ionizable inert gas, said envelope having a transparent portion to form a' viewing window, a plurality of separate electrodes each in the-form of a conductive member bent to a dis- :tinctive indicia shape for sustaining a glow discharge theresorption or obstruction elements.

4. A plural-indicia gaseous glow discharge device, comprising an enclosing envelope containing an ionizable inert gas, said envelope having a transparent portion to form a 'viewing window, a plurality of separate fine-wire glow sus- 'taining electrodes, said plurality of electrodes each being bent toform a distinctive indicia, means to support said electrodes inspaced parallel stacked array, and a plurality oflead-in members equal in number to the number of said electrodes for selectively applying a negative potential to .anydesired electrode, to illuminate said electrode alone by cathode glow.

5. A plural-indicia gaseous glow discharge device, comprising an enclosing envelope containing an ionizable inert gas, said envelope having a transparent portion forming a viewing window, a plurality of ten separate wire electrodes each adapted to sustain an individual cathode glow along its length, each of said wire electrodes being bent to the form of a distinctive indicia from 0 to 9 each of the indicia being free from any closed inductive loops, and a separate lead-in for each electrode for selectively applying a negative potential thereto to sustain a cathode glow along the length thereof.

6. A plural-indicia gaseous glow discharge device, comprising a glass bulb having a header at one end, a plurality of lead-in wires vacuum-tight sealed through said header, said bulb having a transparent portion forming a viewing window, a plurality of fine-wire cathode glow electrodes each of said electrodes being bent to form a distinctive indicia, and all of said electrodes being in optical viewing alignment with said window, and a plurality of metal uprights supported from said header and to which each of said electrodes is individually attached and with the planes of said electrodes being substantially parallel, successive electrodes being spaced from each other and with the said space free from any intervening light absorption or obstruction elements.

7. An indicator device of the kind described, comprising an enclosing bulb having a transparent viewing window at its upper end, a header closing off the lower end of said bulb and having a series of lead-in members sealed therethrough and spaced apart in a substantially circular array, said lead-in members each having a portion extending inwardly of the bulb and substantially parallel to the central longitudinal axis of the bulb, a plurality of wire electrodes each electrode being conductively attached to a corresponding one of said lead-in members and with the planes of said electrodes extending transverse to said longitudinal axis, all of said electrodes being in optical viewing alignment with each other and with said window, successive electrodes being spaced from each other and with the said space free from any intervening light absorption or obstruction elements.

discharge entirely to the length of each wire electrode.

9. A plural-indicia gaseous glow indicator system, comprising in combination a gaseous glow device having an enclosing envelope containing an ionizable medium, a plurality of cathode glow electrodes within said envelope mounted in spaced stacked array, a window in said envelope in viewing alignment with all said electrodes, a source of potential having positive and negative terminals, a plurality of impedances one for each electrode,

.means connecting one end of each impedance to a respective one of said electrodes, means connecting the remaining ends of all said impedances in common to said positive terminal, and means for selectively connecting one of said electrodes substantially directly to said negative terminal for causing only said one of said electrodes to be illuminated by cathode glow.

10. A plural-indicia gaseous glow indicator system according to claim 9 in which each of said electrodes is in the form of a fine wire bent to distinctive indicia formation with the electrodes mounted successively behind each other and behind said Window and each of said impedances is in the form of a resistor, and said selective connecting means includes a commutator having a movable contact element connected to said negative terminal and a series of stationary contacts each connected respectively and substantially directly to a corresponding one of said electrodes.

ll. Plural-indicia indicator apparatus, comprising means defining a viewing plane having adjacent boundary areas, a plurality of similar multiple indicia units each of the gaseous glow discharge type, each. of saidunits comprising a series of skeleton electrodes arranged in stacked spaced array and each electrode formed; to the shape of arespective indicia and arrangedto have a cathode glow'therealong which lis substantially completely visible through the adjacent electrodes of the unit, successive spaced. electrodes being free fromany intervening light absorption or obstruction elements, each of said units being located in. alignment l with a corresponding one of said boundary. areas, and circuit connections including commutator switches for said units for illuminating in any desired combination a single electrode in each of said units. Y v

12. A plural-indicia gaseous glow discharge device, comprising an enclosing envelope containing an ionizable medium and having a transparent portion throughwhich the indicia are viewed, at least three separate glow discharge sustaining skeleton electrodes, in spaced stacked array and in alignment with said portion of said envelope, each of said electrodes being shaped to a distinctive indicia form, the successive electrodes being spaced from each other and free from any intervening light absorption or obstruction elements, and a plurality of lead-in memibers the total number of such lead-in members being equal to the total number of said electrodes.

References Cited in the file of this patent UNITED STATES PATENTS 

